Thermal controlled packaging can be utilized to store and transport materials while maintaining the materials within a desired temperature range. Various temperature conditions may affect the materials, e.g., the performance characteristics of the materials transported and the packaging preferably inhibits the outside conditions' effects upon the materials within the package. Packages may be subject to freezing and elevated temperatures during transport, e.g., through different global regions by both surface and air carriers. Transport temperatures may vary by 30° F. or more. It has been suggested to assume a transport temperature test profile range for varying ambient temperatures for refrigerated transport from about 70° F. to about 100° F., although other temperature profiles have been noted for temperature controlled packaging tests.
Many products are tested and labeled by the manufacturer with recommended storage and transport temperatures. In some instances, temperature-sensitive material can be stored frozen to preserve the material and extend the product life for an extended period of time. It has become more common in the pharmaceutical marketplace to transport and/or store medications at refrigerated temperatures, e.g., from manufacturer's distribution to vendors, during pharmacy and patient transport, etc. Temperature-sensitive products intended for storage may be in liquid or solid form and the manufacturer and/or distributor are typically responsible for the transport temperature ranges specified for the product (e.g., drug) stability and use.
For pharmaceuticals, preferred refrigerated temperatures are typically in the range of about 36° F. to about 46° F. (about 3° C. to about 8° C.) and commonly in the range of about 32° F. to about 46° F. (about 0° C. to about 8° C.), where manufacturers recommend storage without freezing. Temperatures above about 46° F. can spoil the pharmaceutical and/or significantly impair the effectiveness of the pharmaceutical. Temperatures less than 32° F. can cause some pharmaceuticals to freeze, and can spoil the pharmaceutical and/or significantly impairing its effectiveness. Indeed, many manufacturer specifications instruct not to allow the temperature of the product to fall below 32° F. Pharmaceutical manufacturers and international committees such as HACCP/Hazard Analysis Critical Control Point, FDA and IHC International Committee for Harmonization work with standards for transporting vaccines and medicines, requiring them to maintain a refrigerated temperature during transport and in many cases recommending that the materials not freeze. Temperature ranges have been suggested for general storage (between about 25° C.+/−2° C.), for refrigerated storage (5° C.+/−3° C.), and for freezer storage (−20° C.+/−5° C.). Refrigeration is commonly used to prevent products from being spoiled or to avoid potential performance issues with the products as specified by the manufacturers, regulatory agencies (e.g., FDA), and/or other entities. Some manufacturer recommendations have been noted in the general use and storage specifications not to freeze the drug and to store drugs (e.g., human growth hormone drugs, insulin vials) at a refrigerated temperature between 0° C. and 8° C.
Various devices may be used to store products at refrigerated temperatures. Some devices may use a refrigerator unit that requires electricity and a pump that can be both costly and inefficient, requiring a constant power source to operate effectively. Other devices using an ice or gel pack have been noted to have a tradeoff between portability and transportation time. Devices using apparatus to generate thermal energy to provide a temporary source of cooling (e.g., gel, ice packs, and dry ice) or a continuous source of cooling (e.g., refrigeration means powered by electricity) commonly use insulation to reduce heat transfer and improve overall product efficiency.
Temperature-controlled storage devices used for food and beverage products typically have a range of safe storage temperatures from 32-100° F. A change in temperature may not have an effect on the performance or quality of the stored product if it is cycled from a low temperature point to a high temperature point, e.g., due to changes in outside ambient conditions. These types of products may be refrigerated for consumer appeal, and/or to inhibit spoiling (e.g., of milk) if exposed to higher ambient temperature conditions. Medications and other healthcare products can be more sensitive to temperature changes, and temperature changes may affect critical performance characteristics of medications.
Temperature controlled packaging, sometimes referred to as thermal transport devices, have been developed in both a rigid and semi rigid structures. These structures provide barriers or insulation layers to reduce the effects that outside ambient temperatures may have on contents of internal compartments of the devices. The amounts of insulation thickness, material cost and desired insulation performance are common factors considered in designing an insulated package. Increasing insulation thickness may improve the thermal insulation factor to a certain degree, but also can make transport devices more costly and bulky for transportation. Devices used to transport refrigerated medications are more commonly found in rigid materials. Examples of rigid materials blow molded or roto-molded containers that are filled with insulation material or air evacuated to form a vacuum.
Soft-sided coolers are commonly designed with a resilient exterior casing material, a foam insulation barrier and a water resistant inner liner to hold or store ice and/or other cooling products. These devices typically have a limited capacity to cool in higher or elevated ambient temperatures and can be inefficient to provide a stable temperature controlled environment. Thermoelectric coolers use a power source and other electronic components to maintain a refrigerated temperature and sometimes can be quite costly compared to a soft-sided case with re-usable thermal cooling packs. Thermal insulation is one important design factor in the design of a insulated package where heat (Q, SI unit is Joule) is the amount of thermal energy transferred from one object to another due to temperature differences (in thermodynamics heat flows from a hot to a cold body). Heat can be determined according to:Q=mcΔT where m is mass in kg, c is specific heat of the material, and ΔT=Tf−Ti in ° C. (i.e., change in temperature T is the difference between the final temperature and the initial temperature). This formula can be used to calculate the transfer of heat flow from outside ambient temperature conditions, and the heat loss of thermal cooling element to the system or device. The specific heat of water is very high—higher than ice and steam. Water has a very high specific heat, meaning that it heats slowly and cools slowly. The specific heat of a material provides information about how the material heats and cools.
It is not uncommon for patients or doctors to travel for several hours and have a need for a pharmaceutical that needs to be refrigerated until it is administered. Further, products frequently need to be shipped to remote locations that require constant refrigeration with no power source or electricity available. For short travel times of a few hours, materials such as pharmaceuticals can be transported with existing devices, e.g., in a cooler with ice. Coolers or refrigeration units are typically designed for general use and driven by manufacturing costs without needing a controlled temperature range. Environmental chambers can offer a controlled temperature environment but are costly and difficult to transport. Medical or patient transport cases are typically limited to specific uses and may require custom designs to accommodate the manufacturer's recommended storage temperatures. Some transport devices are made of Styrofoam materials with multiple layers of foam and are quite bulky and possibly unsafe, some containing dry ice as the cooling agent. For travel times longer than a few hours, temperature-sensitive materials such as pharmaceutical typically needs to be obtained at the destination location, with the temperature-sensitive material being stored and refrigerated at the destination. Thus, often patients are restricted to travel due to their health conditions and the medications they are prescribed and the availability of those medications.